Kevin Smith has not had a nice time in Europe. The man Peter Biskind lately described as "the George Lucas of the self-abuse set" has just spent the weekend with his wife and daughter in Paris, where a dodgy steak tartare brought on three days of vomiting and chronic diarrhoea. The week before, the Sun described the London opening of his new movie, Jersey Girl, as "the worst British premiere ever". None of the film's stars showed up - Ben Affleck pleaded bronchitis, Liv Tyler was AWOL and Jennifer Lopez, it turns out, was secretly getting married. Nor was the red carpet sullied by so much as a minor soap star or a Britpop has-been. Even Jade had other commitments. To cap it all, the 3am Girls described him as being "fat, bearded and hobbit-like".

Hobbit-like is harsh, but nor is Smith a cuddly clown like Silent Bob. He's more laidback, and speaks in a dry, articulate drawl, liberally punctuated with the adjective "fuckin'". Lounging in a Dorchester suite, preparing to go and talk to his London fans, he looks like the world's best-groomed slacker. "The dude got fuckin' sick," he says of Affleck. "What are you supposed to do?"

He knows the real problem is not the premiere, or the steak tartare, but the fact that his movie got sucked into the all-consuming celebrity saga known as Bennifer. There's little any director could have done against what's been the media equivalent of the Perfect Storm, which is a shame, because Jersey Girl is quite a turning point for Smith. It's no masterpiece, but it's more personal and heartfelt than anything he's done before. There's no Jay and Silent Bob, the Cheech and Chong-like wasters Smith and his buddy Jason Mewes played in his previous five movies. Instead we get Affleck coping with the death of his wife and the responsibilities of single parenthood. In Jersey. Which means no discussions of private contractors on the Death Star, no barely sublimated homosexuality, and definitely no "snootchie bootchies!" He's not going all mainstream on us is he?

"No, I never want to become John Hughes where suddenly I stop making Pretty In Pink and start making, like, Curly Sue and Home Alone. I figure the next time I make a movie about being a father will be when my kid is, like, pounding tons of drugs and having sex and she'll be like, 'I hate you dad!' And I'll be, like, 'I hate you Jersey Girl!'"

It was Affleck's idea to cast J-Lo. This was at a time when nobody, Smith included, had any idea they were an item, and their recently wrapped Gigli was being touted as a contender for Golden Globes rather than Razzies. "There were some people who were like, 'If they're dating, dude you're in trouble.' I don't believe in that kind of thing. But I still feel to this day that the work was stronger because of their relationship." The first hint Smith got that there might be a problem was after a test screening early last year. When asked, 'How would you recommend the film?' one focus group member replied, "I'd tell my friends to go see this movie because J-Lo dies." Then Gigli came out, which was "like throwing fuckin' fuel on the fire. Nuclear-reinforced fuel that sent up not just flames but a toxic fuckin' cloud as well, that then attached itself to our movie."

Less charitable observers would say Smith got what he deserved for trying to play the Hollywood A-list. Let's not forget he was one of the most genuine amateurs ever to break into movies. His debut, Clerks, was shot with $28,000 of credit card loans, with his friends as the cast, in the convenience store where he worked. Despite his undeniable talent for dialogue, a lot of people predicted he wouldn't last long. But for all the professional snobbery, condescending reviews and even death threats, he's still here 10 years later, and his self-created universe is still expanding. His movies do well - Jay And Silent Bob Strike Back took $30m in US theatres and another $36m in DVD sales. His characters have featured in comics, music videos, TV cartoons, video games, even as action figures. He also has a sideline writing for comics like Daredevil and Spider-Man. Added to which, he's become a seasoned public speaker, touring US colleges doing Q&A sessions - which have been so successful, they've put together a DVD of them.

So life has gotten better, but it's also gotten heavier. His "heterosexual life partner" Jason Mewes has been recovering from addiction to heroin, with Smith's support. There's an eerie moment on the DVD of his live show where Smith brings Mewes on stage at a packed campus auditorium and proceeds to talk about the crazy stuff Mewes does as if he's not there. Mewes himself, looking strung-out and androgynous, sits there in mute acquiescence. It's Bob and Silent Jay.

The live show at least ends his European expedition on something of a high. Smith lists talking to his fans as the third favourite part of his job, after writing and editing (directing is "a necessary evil"), and when he takes the stage it's clear to see why. The self-abuse set loves him. Smith is one of them, with the same nerdy, pop-cultural, preoccupations. There's a lot more A than Q. He gets his own back on the 3am Girl ("If I'm a hobbit this fuckin' bitch is an orc!"). He's upfront about Mewes' heroin addiction and his rehabilitation. He's been clean for over a year now, and is currently raising Red Bull-fuelled hell in LA with Jack Osbourne - they call themselves "Project Falcon". He talks about sharing Harvey Weinstein's private jet, and he professes his ignorance of British history and geography ("there's really a place called Crystal Palace? How gay is that?"). More than anything, he makes fun of himself, even confessing how, as a plump teenager, he used to impress his girlfriend by dressing in a long black leather coat and a Batman T-shirt, hanging out mysteriously on the roof of the local pharmacy.

Four and a half hours later, Smith is ready to go home. Which might be a little difficult since home is a four-storey pad in the Hollywood hills that used to belong to a certain Ben Affleck. This doesn't mean he's "gone Hollywood", he insists. All it means is that his wife, former USA Today journalist Jennifer Schwalbach, is more of an LA woman than a Jersey girl, and she calls the shots. By way of confirmation, he's wearing a sports shirt embroidered with the words "Jennifer's bitch".

If anything, Smith is moving further away from Hollywood. His next project was supposed to be a big-budget version of cult series The Green Hornet, but he now says he'd rather just write it and let someone else direct. "I didn't get into this business to make comic-book movies or big action movies. I got into this business to make movies like Clerks. That's all I wanted to do." So instead, he's got a small ($250,000) project starting in October. No clues as to the story though, "let's just say I won't need Affleck for this". Could he afford Affleck for this? He cracks into a smirk. "Oh I think Ben could be pretty cheap right now."

· Jersey Girl is out now. An Evening With Kevin Smith is out on DVD on Monday (£19.99, Columbia TriStar)